- 學位論文
應用LTPP資料庫探討鋪面參數變異性對鋪面績效分析的影響
Using LTPP Database to Study the Effect of parameter Variability on Pavement Performance Analysis
摘要
近年來鋪面相關的研究已將隨機的概念結合力學公式用於鋪面的分析與設計。然而這些設計法仍有一些缺點，因它們只考慮一些設計參數的變異性，如材料性質或鋪面厚度，但無法說明設計之鋪面能達到需求績效的可靠度或此鋪面可能破壞的機率。目前國內在鋪面的分析與設計中，多以考慮材料變異為主。但道路鋪築過程會因施工的不確定性導致厚度不均的問題，故探討厚度變異性的影響有其必要性。現今因鋪面的設計過程中輸入參數的不確定性，使得所設計的鋪面在其車輛荷重作用下鋪面績效亦充滿著不確定性與風險。以工程品管與風險管理的觀念，必須對所設計鋪面績效的可靠度有充分的掌握，故本研究將發展力學與機率模式結合之鋪面績效分析程式，並用美國LTPP資料庫驗證鋪面績效分析程式的正確性，以作為鋪面參數變異性影響分析之依據。 本研究所發展之鋪面隨機績效程式將探討鋪面參數變異性對鋪面分析之影響。首先由美國長期鋪面成效計畫(LTTP, Long-Term Pavement Performance)資料庫中選擇八組試驗路段，取得每個路段九組FWD (Falling Weight Deflectometer)試驗結果，反算求得各路段材料性質與鋪面厚度，並利用統計方法求得鋪面參數之平均值與變異係數。接著將蒙地卡羅模擬法、有限元素法與塑性力學理論結合發展成隨機鋪面績效分析程式，再將反算取得材料之統計參數帶入隨機鋪面績效分析程式中進行結構分析與破壞分析，分別求得位移與應力之結果以及車轍與疲勞龜裂之結果，並探討鋪面參數變異性對LTPP試驗路段鋪面結構分析與破壞分析的影響，本研究之結果將有助於現有鋪面分析與設計方法之提升。
並列摘要
Due to the development of theory and numerical method, the pavement design is gradually changing from the mechanics-empirical approach to the mechanical design method. Since the material properties variation is shown in the construction process, the pavement design programs had considered the material variability in the design analysis. However, their considerations of material variation are based on simple statistics approach. In this study, the stochastic finite element program is developed, and it is incorporated with the probabilistic model to compute the statistical parameters of pavement response, and the results can be used for the risk analysis of pavement design. The validation of the stochastic pavement analysis program is verified by the Long-Term Pavement Performance program database developed in the United State. In this study, the eight LTPP test sections are selected for the backcalculation analysis to compute the statistical parameters of pavement material and thickness. Then the effect of the material variation and thickness to the pavement structural response are investigated. Finally, the results of stochastic finite element analysis are incorporated with distress models to evaluate the mean and variance of rutting and fatigue cracking under the repeated traffic loading. The results of this study can improve the current pavement design and analysis.